Leadless Electrocardiogram (ECG) Evaluation Study (LECG)

Leadless ECG Evaluation Study - Prospectively, Randomized, Cross-over, Multi-center, Interventional, Post-market Release Study to Evaluate the LECG System.

The leadless electrocardiogram (LECG) is a new technology incorporated into the Consulta CRT-P to obtain an ECG signal from the Consulta CRT-P similar to a surface ECG obtained from the device programmer (PECG) or an external ECG machine. The purpose of the study is to obtain more data on leadless ECG to determine whether LECG during standard CRT follow-up can indeed adequately replace surface ECG and to evaluate if it can be used during remote follow-up evaluations.

The leadless electrocardiogram (LECG) is a new technology incorporated into the Consulta CRT-P to obtain an ECG signal from the Consulta CRT-P similar to a surface ECG obtained from the device programmer (PECG) or an external ECG machine. The LECG signals are measured from three electrodes mounted on the outside of the pacemaker housing and provides an electrical far field signal of the electrical activity of the heart. The LECG provides three ECG channels as different projections of the electrical activity of the heart, similar to the surface ECG. Clinical interest of LECG is threefold. First, ECG recordings are routinely used to perform pacemaker and cardiac resynchronization systems in-office follow-up mainly to determine pacing thresholds. Connection of ECG electrodes to the patient as well as the time needed to acquire an acceptable ECG signal during routine follow-up could be saved using LECG which would make follow-up easier and less time consuming. Secondly, connecting ECG electrodes requires the patient to be present at the clinic for the follow-up. Use of LECG in conjunction with a transmitting system will allow remote patient follow-up. In that case, correct ventricular capture confirmation by the LECG is of key importance. Finally, LECG stored in device memory at the time of an arrhythmia episode occurrence, can help better classify it. The following factors might influence the quality of the LECG and/or the axis of the LECG: temporal changes of the electrode tissue interface due to device pocket healing process changes in device position and orientation over time body motion poor LECG contact due to oversized device pocket with replacement procedure. The purpose of this study is to obtain more data on leadless ECG (LECG) to determine whether LECG during standard CRT follow-up can indeed adequately replace surface ECG and to evaluate if it can be used during remote follow-up evaluations.

Measurement of pacing thresholds are done first with the support of a leadless ECG provided by the implanted device

Proportion of Patients With LECG Performing Clinically Equivalent to PECG During Standard Pacemaker Follow-up Procedure.

During CRT-P standard follow-up, ECG is used to determine atrial, left and right ventricular pacing thresholds. As primary endpoint, we will consider the proportion of patients for which for all leads LECG provides pacing threshold values that are clinically equivalent to those obtained with PECG taken as reference. The analysis will be performed on data collected at the 1-Month Follow-Up visit when the device pocket healing process is completed. Clinical equivalence will be defined as the LECG threshold values being no more than 0.5 volts different from the PECG threshold values.

The investigator will simulate loss of capture (LOC) at 1-Month Follow-Up visit by printing strips of LOC in both ventricular leads, LOC in LV lead only, LOC in RV lead only, no LOC. One strip randomly selected among them by the study manager will be submitted to an independent reviewer. With help of the PHD template LECG strips (intrinsic, RV paced, LV paced, BiV paced) of this patient, he/she will determine which lead is capturing. The endpoint is the proportion of correct classifications of ventricular capture done by then independent reviewer of LECG.

Two parameters will be used to evaluate LECG changes between PHD and 1-Month on the same LECG vector: intrinsic R wave amplitude and P waves visibility (selection the LECG vector at PHD with best combination of the highest R wave and most visible P wave). R wave amplitude measurements as well as P wave visibility assessment will be done by the independent reviewer. The endpoints evaluated are: mean R wave changes from PHD to 1-month proportion of patients with stable P wave visibility at PHD and 1-Month (meaning both visits visible or both visits not visible).

The two following parameters will be used to compare the quality of LECG in new implants versus device replacements at PHD and 1-Month on the same LECG vector: Intrinsic R wave amplitude P waves visibility The LECG vector at PHD with best combination of the highest R wave and most visible P wave will be selected. R wave amplitude measurements as well as P wave visibility assessment will be done by the independent reviewer. The endpoints will be: comparison of mean R wave values at PHD and 1-month comparison of proportion of patients with P wave visible at PHD and 1-month.

The intrinsic R wave amplitude and P waves visibility will be taken to evaluate the effect of posture changes and artifact-inducing maneuvers on the quality of LECG at the 1-Month Follow-Up visit (LECG vector with best combination of the highest R wave and most visible P wave). The endpoints will be R wave amplitude and P wave visibility in different positions (meaning visible or not visible in both positions). R wave changes and proportion of patients with stable P waves visibility at lying position versus other positions will be calculated by an independent reviewer.

Evaluation of Factors Such as Device Rotation, Device Fixation, Device Side Facing the Skin, Position of Lead Loops in the Pocket, Use of Antiseptic Solution, Skin Type, Body Mass Index on the Quality of Leadless ECG.

The following factors will be evaluated to investigate whether they influence the LECG quality: device position (subcutaneous, submuscular, etc) device rotation device fixation device side facing the skin position of lead loops in the pocket use of antibiotics in the pocket skin type (loose, normal, firm) body mass index (BMI) The endpoints will be: describe R wave amplitude values describe proportion of patients with P wave visible on intrinsic LECG strips recorded at 1-Month FU.

Inclusion Criteria: patient with a CRT-P indication and patient who has signed an informed consent form. Exclusion Criteria: patient younger than 18 years and/or unable to complete the 1-Month Follow-up visit and/or legally incompetent or illiterate and therefore unable to provide an informed consent